In the microelectronics industry, before integrated circuit (IC) chips are packaged in an electronic component, testing is essential to ensure that electronic components perform the function for which they were designed. The testing is commonly done both at room temperature and at elevated temperatures to test functionality, and at elevated temperatures with forced voltages and currents to burn the chips in and to test the reliability of the integrated circuit to screen out early failures.
Contemporary high density testing probes for integrated circuits are typically fabricated on a support substrate from groups of elongated conductor beams which fan inwardly towards a central location where each conductor has an end which corresponds to a contact location on the integrated circuit chip to be tested. The conductors are cantilever over an aperture in the support substrate. Because the cantilevered beams are easily displaced and deformed after compressive force in the testing process, the high density testing probes only survive a limited number of test operations.
The present invention provides a probe structure which overcomes the permanent damage or displacement of the conductor beams which occurs in currently available probes when they are repeatedly placed in contact with a device under test. This is achieved by a new probe technology, according to the present invention, using fine wires embedded in the thermally stable elastomer. For the probe technology, according to the present invention, high compliance is achieved at low contact force using an elastomer which has a combination of thermal stabilitity, resilience, good mechanical properties, and processibility.